rusty_bind_parser/

binding_module.rs

//
// Wildland Project
//
// Copyright © 2022 Golem Foundation,
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License version 3 as published by
// the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

use std::collections::HashSet;

use proc_macro2::{Ident, Span, TokenStream};
use quote::quote;
use syn::token::Comma;
use syn::{
    parse_quote,
    parse_str,
    Abi,
    Field,
    Item,
    ItemEnum,
    ItemForeignMod,
    ItemMod,
    Type,
    Variant,
};

use crate::ffi_helper_traits::get_ffi_helper_trait;
use crate::trait_function_helpers::get_trait_functions;
use crate::utils::BuildContext;
use crate::DROP_FUNCTION_SYMBOL_NAME;
/// An implementation of a translator that can parse some specific Rust modules and
/// prepare extern functions that are part of the static library interface.
///
use crate::{
    binding_types::*,
    cpp::{generate_cpp_file, swig_generator::generate_swig_based_on_wrappers},
    enum_helpers::*,
    extern_functions_utils::*,
    extern_module_translator::ExternModuleTranslator,
    swift::{generate_c_externs_file, generate_swift_file},
    EXPORTED_SYMBOLS_PREFIX,
};

pub struct GeneratedFilesContent {
    pub cpp_header: String,
    pub swift_header: String,
    pub cpp_externs: String,
    pub swig_interface: String,
}

// Feature names that are read from std::env::vars are uppercased and every '-' is replaced by '_'.
// This class guarantees that the same transformation will be applied to every feature name regardless its origin.
#[derive(Debug, Clone)]
pub struct CargoFeature {
    val: String,
}

impl CargoFeature {
    pub fn new<T>(val: &T) -> Self
    where
        T: AsRef<str> + ?Sized,
    {
        Self {
            val: val.as_ref().to_uppercase().replace('-', "_"),
        }
    }
}

impl PartialEq for CargoFeature {
    fn eq(&self, other: &Self) -> bool {
        self.val == other.val
    }
}

/// The structure consist of:
/// - extern blocks translator module, i.e. `extern "Rust"` and `extern "Traits"`,
/// - generated extern functions that wrap the actual user's methods.
///
pub struct BindingModule {
    extern_module_translator: ExternModuleTranslator,
    wrappers_impls: TokenStream,
    extern_functions: Vec<ExternFunction>,
}

impl BindingModule {
    /// The method translates Rust module containing `extern "Rust"` and generates all
    /// needed wrappers.
    ///
    pub fn translate_module(module: ItemMod, context: &BuildContext) -> anyhow::Result<Self> {
        let enums: HashSet<ItemEnum> = get_enums_from_module(&module, context)?
            .into_iter()
            .collect();

        let module_name = &module.ident;
        let mut extern_module_translator = ExternModuleTranslator::new(enums.clone());
        if let Some(ext_rust_module) = BindingModule::get_extern_mod_from_module(&module, "Rust") {
            extern_module_translator.parse_items_in_extern_rust_module(ext_rust_module, context)?;
        }
        if let Some(ext_trait_module) = BindingModule::get_extern_mod_from_module(&module, "Traits")
        {
            extern_module_translator.translate_trait_external_modules(ext_trait_module, context)?;
        }
        if let Some(ext_exception_trait_module) =
            BindingModule::get_extern_mod_from_module(&module, "ExceptionTrait")
        {
            extern_module_translator
                .translate_exception_trait_external_module(ext_exception_trait_module, context)?;
        }

        let mut result = BindingModule {
            extern_module_translator,
            wrappers_impls: Default::default(),
            extern_functions: Default::default(),
        };
        result.create_wrappers_for_custom_types();
        result.create_complex_enum_getters(&enums);
        result.create_wrappers_for_exception_trait();
        result.create_wrappers_for_traits();
        result.create_wrappers_for_global_functions();
        result.create_wrappers_for_results(enums)?;
        result.create_wrappers_for_builtins()?;
        result.create_wrappers_for_clones();
        result.create_wrappers_for_strings()?;
        result.assign_trait_impls();
        result.add_ffi_helper_traits();
        result.wrappers_impls.extend(
            result
                .extern_functions
                .iter()
                .map(|extern_function| extern_function.tokens.clone()),
        );
        // Panic wrapper needs to be registered as en extern function but it's call should not be put into the `interface.rs`
        // that's why it should be registered after all extern functions have been added to the `wrappers_impls`
        result.register_panic_wrapper();
        let wrappers_impls = &result.wrappers_impls;
        result.wrappers_impls = quote!( mod #module_name { #![allow(warnings, unused)] use super::*; #wrappers_impls } );
        Ok(result)
    }

    /// Method generates C++, Swift and SWIG glue code. The latter is needed to generate glue code
    /// for other target languages like Java, C#, Python etc.
    ///
    pub fn generate_binding_files(&self) -> GeneratedFilesContent {
        GeneratedFilesContent {
            cpp_header: generate_cpp_file(&self.extern_module_translator, &self.extern_functions),
            swift_header: generate_swift_file(&self.extern_module_translator),
            cpp_externs: generate_c_externs_file(
                &self.extern_module_translator,
                &self.extern_functions,
            ),
            swig_interface: generate_swig_based_on_wrappers(&self.extern_module_translator),
        }
    }

    /// Returns the whole generated code in the form of a token stream.
    /// It wraps the derived module into another one in order to avoid custom types
    /// and wrappers types names collision.
    ///
    pub fn get_tokens(&self) -> TokenStream {
        self.wrappers_impls.clone()
    }

    /// Helper method - returns a foreign module from within the Rust module.
    ///
    fn get_extern_mod_from_module<'a>(
        module: &'a ItemMod,
        extern_lang: &str,
    ) -> Option<&'a ItemForeignMod> {
        module.content.as_ref().and_then(|(_, items)| {
            items.iter().find_map(|module_item| match module_item {
                Item::ForeignMod(
                    rust_module @ ItemForeignMod {
                        abi:
                            Abi {
                                name: Some(lang), ..
                            },
                        ..
                    },
                ) if lang.value() == extern_lang => Some(rust_module),
                _ => None,
            })
        })
    }

    fn register_extern_function(&mut self, function: ExternFunction) {
        self.extern_functions.push(function);
    }

    fn register_panic_wrapper(&mut self) {
        let ex_fn = ExternFunction {
            arguments: vec![WrapperType {
                original_type_name: syn::parse_str("String").unwrap(),
                wrapper_name: "String".to_string(),
                rust_type: RustWrapperType::Custom,
                reference_parameters: Some(ReferenceParameters {
                    is_static: true,
                    is_mut: false,
                    boxed: false,
                }),
                impl_traits: vec![],
            }],
            return_type: None,
            name: format!("{}$fatalError", EXPORTED_SYMBOLS_PREFIX),
            tokens: parse_str("panic!(message);").unwrap(),
        };
        self.extern_functions.push(ex_fn);
    }

    fn create_complex_enum_getters(&mut self, enums: &HashSet<ItemEnum>) {
        enums
            .iter()
            .filter(|enum_item| !is_primitive_enum(enum_item))
            .for_each(|ce| self.complex_enum_getter(ce));
    }

    fn complex_enum_getter(&mut self, complex_enum: &ItemEnum) {
        let enum_ident = &complex_enum.ident;
        let variant_wrapper_structs = complex_enum
            .variants
            .iter()
            .map(|v| self.create_variant_struct_wrapper(v, complex_enum))
            .collect::<TokenStream>();
        let many_fields_variants_wrapper_getters =
            self.create_and_register_many_fields_variants_wrapper_getters(complex_enum);
        let single_field_variants_getters =
            self.create_and_register_single_field_variants_wrapper_getters(complex_enum);

        if complex_enum
            .variants
            .iter()
            .any(|v| !is_ignored_variant(v) && !is_unit_variant(v))
        {
            let enum_impl_block = quote! {
                impl #enum_ident {
                    #many_fields_variants_wrapper_getters
                    #single_field_variants_getters
                }
            };
            self.wrappers_impls.extend(variant_wrapper_structs);
            self.wrappers_impls.extend(enum_impl_block);
        }
    }

    fn create_and_register_many_fields_variants_wrapper_getters(
        &mut self,
        complex_enum: &ItemEnum,
    ) -> TokenStream {
        let enum_ident = &complex_enum.ident;
        complex_enum
            .variants
            .iter()
            .filter(|v| is_many_fields_variant(v))
            .map(|v| {
                let getter_name = variant_getter_ident(v);
                let wrapper_name = variant_wrapper_ident(enum_ident, &v.ident);
                self.register_variant_getter_extern_function(complex_enum, v);
                quote! {fn #getter_name(&self) -> #wrapper_name {
                    #wrapper_name(self.clone())
                }}
            })
            .collect::<TokenStream>()
    }

    fn create_and_register_single_field_variants_wrapper_getters(
        &mut self,
        complex_enum: &ItemEnum,
    ) -> TokenStream {
        complex_enum
            .variants
            .iter()
            .filter(|v| is_single_field_variant(v))
            .filter_map(|v| {
                let field = &get_fields(v).unwrap()[0];
                let variant_ident = &v.ident;
                match &field_type(field) {
                    FieldType::Type(field_type) => {
                        let return_type: Ident = syn::parse_str(field_type).unwrap();
                        let fn_ident = variant_getter_ident(v);
                        let field_retrieve = if is_primitive_field(field) {
                            quote! {*field}
                        } else {
                            quote! {field.clone()}
                        };
                        let field_match = if let Some(name) = field_name(field) {
                            let name = syn::parse_str::<Ident>(&name).unwrap();
                            quote! {{#name: field}}
                        } else {
                            quote! {(field)}
                        };
                        self.register_variant_getter_extern_function(complex_enum, v);
                        Some(quote! {
                            fn #fn_ident(&self) -> #return_type {
                                match &self {
                                    Self::#variant_ident #field_match => #field_retrieve,
                                    _ => panic!(),
                                }
                            }
                        })
                    }
                    FieldType::Ignored => None,
                }
            })
            .collect::<TokenStream>()
    }

    fn create_variant_struct_wrapper(
        &mut self,
        variant: &Variant,
        enum_item: &ItemEnum,
    ) -> TokenStream {
        let enum_ident = &enum_item.ident;
        let wrapper_ident = variant_wrapper_ident(enum_ident, &variant.ident);
        let struct_tokens = quote! {#[derive(Clone)] pub struct #wrapper_ident(#enum_ident);};
        get_fields(variant)
            .map(|fields| {
                if fields.len() > 1 {
                    let field_getters =
                        self.create_and_register_variant_fields_getters(fields, enum_item, variant);
                    self.register_drop_function_for_variant_wrapper(wrapper_ident.to_string());
                    self.register_clone_function_for_variant_wrapper(wrapper_ident.to_string());
                    quote! {
                        #struct_tokens
                        impl #wrapper_ident {
                            #field_getters
                        }
                    }
                } else {
                    // variants with only one field are returned directly, without a wrapper
                    // unit variants are not returned at all
                    quote! {}
                }
            })
            .unwrap_or_default()
    }

    fn register_drop_function_for_variant_wrapper(&mut self, wrapper_name: String) {
        let ext_fun = create_drop_extern_function(WrapperType {
            original_type_name: syn::parse_str(&wrapper_name).unwrap(),
            wrapper_name,
            rust_type: RustWrapperType::Custom,
            reference_parameters: None,
            impl_traits: vec![],
        });
        self.register_extern_function(ext_fun);
    }

    fn register_clone_function_for_variant_wrapper(&mut self, wrapper_name: String) {
        let ext_fun = create_clone_extern_function(WrapperType {
            original_type_name: syn::parse_str(&wrapper_name).unwrap(),
            wrapper_name,
            rust_type: RustWrapperType::Custom,
            reference_parameters: None,
            impl_traits: vec![],
        });
        self.register_extern_function(ext_fun);
    }

    fn create_and_register_variant_fields_getters(
        &mut self,
        fields: &syn::punctuated::Punctuated<syn::Field, Comma>,
        enum_item: &ItemEnum,
        variant: &Variant,
    ) -> TokenStream {
        fields
            .iter()
            .enumerate()
            .map(|(idx, field)| {
                let field_type = field_type(field).unwrap_type();
                let return_type: TokenStream = field_type.parse().unwrap();
                let fn_ident = field_getter_ident(field, idx);
                let (fields_match, field_name) = if let Some(field_name) = &field.ident {
                    (quote! {{#field_name, ..}}, field_name.clone())
                } else {
                    let fields_match = (0..fields.len())
                        .map(|idx| format!("_{idx}"))
                        .collect::<Vec<_>>()
                        .join(", ")
                        .parse::<TokenStream>()
                        .unwrap();
                    (
                        quote! {(#fields_match)},
                        Ident::new(&format!("_{idx}"), Span::call_site()),
                    )
                };

                self.register_field_getter_extern_function(enum_item, variant, field, idx);

                let variant_ident = &variant.ident;
                let enum_ident = &enum_item.ident;
                quote! {
                    fn #fn_ident(&self) -> #return_type {
                        match &self.0 {
                            #enum_ident::#variant_ident #fields_match => (*#field_name).clone(),
                            _ => panic!(),
                        }
                    }
                }
            })
            .collect::<TokenStream>()
    }

    fn register_field_getter_extern_function(
        &mut self,
        enum_item: &ItemEnum,
        variant: &Variant,
        field: &Field,
        field_idx: usize,
    ) {
        let function = create_field_getter_function(enum_item, variant, field, field_idx);
        let extern_function = create_extern_function_for_custom_type(
            variant_wrapper_ident(&enum_item.ident, &variant.ident)
                .to_string()
                .as_str(),
            &function,
        );
        self.register_extern_function(extern_function);
    }

    fn register_variant_getter_extern_function(&mut self, enum_item: &ItemEnum, variant: &Variant) {
        let function = create_variant_getter_function(enum_item, variant);
        if let Some(function) = function {
            let extern_function = create_extern_function_for_custom_type(
                enum_item.ident.to_string().as_str(),
                &function,
            );
            self.register_extern_function(extern_function);
        }
    }

    fn assign_trait_impls(&mut self) {
        let declared_impls = self.extern_module_translator.declared_impls.to_owned();
        for (type_, traits) in declared_impls {
            if let Some(wt) = self
                .extern_module_translator
                .user_custom_types
                .to_owned()
                .into_keys()
                .find(|wt| wt.wrapper_name == *type_)
            {
                let (mut wt, funcs) = self
                    .extern_module_translator
                    .user_custom_types
                    .remove_entry(&wt)
                    .unwrap();

                for trait_ in traits {
                    if let Some(funcs) =
                        get_trait_functions(wt.wrapper_name.to_owned(), trait_.to_owned())
                    {
                        funcs.iter().for_each(|function| {
                            self.register_extern_function(create_extern_function_for_custom_type(
                                &wt.wrapper_name,
                                function,
                            ))
                        });
                        wt.impl_traits.push(RustTrait {
                            name: trait_.to_owned(),
                            has_methods: !funcs.is_empty(),
                        });
                    }
                }

                self.extern_module_translator
                    .user_custom_types
                    .insert(wt, funcs);
            }
        }
    }

    fn add_ffi_helper_traits(&mut self) {
        let mut all_impl_traits: HashSet<String> = HashSet::new();
        for (_, traits) in self.extern_module_translator.declared_impls.iter() {
            all_impl_traits.extend(traits.clone());
        }

        for trait_ in all_impl_traits {
            if let Some(definition) = get_ffi_helper_trait(trait_) {
                self.wrappers_impls.extend(definition);
            }
        }
    }

    fn create_wrappers_for_custom_types(&mut self) {
        self.extern_module_translator
            .user_custom_types
            .iter()
            .flat_map(|(custom_type, functions)| match custom_type {
                WrapperType {
                    original_type_name: _,
                    wrapper_name,
                    rust_type:
                        RustWrapperType::Custom | RustWrapperType::ArcMutex | RustWrapperType::Arc,
                    ..
                } => functions
                    .iter()
                    .map(|function| create_extern_function_for_custom_type(wrapper_name, function))
                    .collect(),
                _ => vec![],
            })
            .collect::<Vec<_>>()
            .into_iter()
            .for_each(|f| self.register_extern_function(f));
    }

    fn create_wrappers_for_results(&mut self, enums: HashSet<ItemEnum>) -> anyhow::Result<()> {
        self.extern_module_translator
            .rust_types_wrappers.clone()
            .unordered_iter()
            .map(|wrapper| match wrapper {
                WrapperType {
                    original_type_name,
                    wrapper_name,
                    rust_type: RustWrapperType::Result(ok_wrapper_type, exceptions_wrapper_type),
                    ..
                } => {
                    let mut local_extern_mod_translator = ExternModuleTranslator::new(enums.clone());
                    let ok_type = &ok_wrapper_type.original_type_name;
                    let exc_type = &exceptions_wrapper_type.original_type_name;
                    let from_ok_extern_function = from_ok_extern_function(wrapper, ok_wrapper_type);
                    let from_err_extern_function = from_err_extern_function(wrapper, exceptions_wrapper_type);
                    let (_, is_ok_function) = local_extern_mod_translator
                        .translate_function(&parse_quote! { fn is_ok(self: &#original_type_name) -> bool; })?;
                    let is_ok_extern_function = create_extern_function_for_custom_type(
                        wrapper_name,
                        &is_ok_function,
                    );
                    let (_, unwrap_unchecked_function) = local_extern_mod_translator
                        .translate_function(
                            &parse_quote! { fn unwrap(self: #original_type_name) -> #ok_type; },
                        )?;
                    let unwrap_unchecked_extern_function = create_extern_function_for_custom_type(
                        wrapper_name,
                        &unwrap_unchecked_function,
                    );
                    let (_, unwrap_err_unchecked_function) = local_extern_mod_translator
                        .translate_function(
                            &parse_quote! { fn unwrap_err_unchecked(self: #original_type_name) -> #exc_type; },
                        )?;
                    let unwrap_err_unchecked_extern_function = create_extern_function_for_custom_type(
                        wrapper_name,
                        &unwrap_err_unchecked_function,
                    );
                    Ok(vec![
                        from_ok_extern_function,
                        from_err_extern_function,
                        is_ok_extern_function,
                        unwrap_unchecked_extern_function,
                        unwrap_err_unchecked_extern_function,
                    ])
                },
                _ => Ok(vec![])
            })
            .collect::<anyhow::Result<Vec<_>>>()?
            .into_iter()
            .flatten()
            .for_each(|f| self.register_extern_function(f));
        Ok(())
    }

    fn create_option_extern_functions(
        wrapper: &WrapperType,
        inner_type: &WrapperType,
        original_type_name: &Type,
        wrapper_name: &str,
        local_extern_mod_translator: &mut ExternModuleTranslator,
    ) -> anyhow::Result<Vec<ExternFunction>> {
        let inner_type = &inner_type.original_type_name;

        let (_, new_function) = local_extern_mod_translator.translate_function(
            &parse_quote! { fn from(val: #inner_type) -> #original_type_name; },
        )?;
        let wrapper_without_generics = WrapperType {
            original_type_name: syn::parse_str("Option").unwrap(),
            ..wrapper.clone()
        };
        let from_extern_function = create_extern_associated_function_for_custom_type(
            wrapper_without_generics,
            &new_function,
        );
        let (_, new_function) = local_extern_mod_translator
            .translate_function(&parse_quote! { fn default() -> #original_type_name; })?;
        let wrapper_without_generics = WrapperType {
            original_type_name: syn::parse_str("Option").unwrap(),
            ..wrapper.clone()
        };
        let default_extern_function = create_extern_associated_function_for_custom_type(
            wrapper_without_generics,
            &new_function,
        );

        let (_, is_some_function) = local_extern_mod_translator.translate_function(
            &parse_quote! { fn is_some(self: &#original_type_name) -> bool; },
        )?;
        let is_ok_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &is_some_function);
        let (_, unwrap_unchecked_function) = local_extern_mod_translator.translate_function(
            &parse_quote! { fn unwrap(self: #original_type_name) -> #inner_type; },
        )?;
        let unwrap_unchecked_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &unwrap_unchecked_function);
        Ok(vec![
            from_extern_function,
            default_extern_function,
            is_ok_extern_function,
            unwrap_unchecked_extern_function,
        ])
    }

    fn create_vector_extern_functions(
        wrapper: &WrapperType,
        inner_type: &WrapperType,
        original_type_name: &Type,
        wrapper_name: &str,
        local_extern_mod_translator: &mut ExternModuleTranslator,
    ) -> anyhow::Result<Vec<ExternFunction>> {
        let inner_type_original = &inner_type.original_type_name;

        let (_, new_function) = local_extern_mod_translator
            .translate_function(&parse_quote! { fn new() -> #original_type_name; })?;
        let wrapper_without_generics = WrapperType {
            original_type_name: syn::parse_str("Vec").unwrap(),
            ..wrapper.clone()
        };
        let new_extern_function = create_extern_associated_function_for_custom_type(
            wrapper_without_generics,
            &new_function,
        );

        let (_, with_capacity_function) = local_extern_mod_translator.translate_function(
            &parse_quote! { fn with_capacity(capacity: usize) -> #original_type_name; },
        )?;
        let wrapper_without_generics = WrapperType {
            original_type_name: syn::parse_str("Vec").unwrap(),
            ..wrapper.clone()
        };
        let with_capacity_extern_function = create_extern_associated_function_for_custom_type(
            wrapper_without_generics,
            &with_capacity_function,
        );

        let get_extern_function =
            create_get_from_vec_extern_function(wrapper.clone(), inner_type.clone());

        let (_, push_function) = local_extern_mod_translator.translate_function(
            &parse_quote! { fn push(self: &#original_type_name, obj: #inner_type_original); },
        )?;
        let push_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &push_function);

        let (_, as_mut_ptr_function) = local_extern_mod_translator
            .translate_function(&parse_quote! { fn as_mut_ptr(self: &#original_type_name) -> *mut #inner_type_original; })?;
        let as_mut_ptr_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &as_mut_ptr_function);

        let (_, len_function) = local_extern_mod_translator
            .translate_function(&parse_quote! { fn len(self: &#original_type_name) -> usize; })?;
        let len_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &len_function);

        let (_, set_len_function) = local_extern_mod_translator.translate_function(
            &parse_quote! { fn set_len(self: &#original_type_name, new_len: usize); },
        )?;
        let set_len_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &set_len_function);
        Ok(vec![
            new_extern_function,
            with_capacity_extern_function,
            get_extern_function,
            push_extern_function,
            len_extern_function,
            set_len_extern_function,
            as_mut_ptr_extern_function,
        ])
    }

    fn create_wrappers_for_builtins(&mut self) -> anyhow::Result<()> {
        self.extern_module_translator
            .rust_types_wrappers
            .clone()
            .unordered_iter()
            .map(|wrapper| match wrapper {
                WrapperType {
                    original_type_name,
                    wrapper_name,
                    rust_type: RustWrapperType::Option(inner_type),
                    ..
                } => BindingModule::create_option_extern_functions(
                    wrapper,
                    inner_type,
                    original_type_name,
                    wrapper_name,
                    &mut self.extern_module_translator,
                ),
                WrapperType {
                    original_type_name,
                    wrapper_name,
                    rust_type: RustWrapperType::Vector(inner_type),
                    ..
                } => BindingModule::create_vector_extern_functions(
                    wrapper,
                    inner_type,
                    original_type_name,
                    wrapper_name,
                    &mut self.extern_module_translator,
                ),
                _ => Ok(vec![]),
            })
            .collect::<anyhow::Result<Vec<_>>>()?
            .into_iter()
            .flatten()
            .for_each(|f| self.register_extern_function(f));
        Ok(())
    }

    /// Generates impl blocks for each custom user's Rust trait exposed via FFI
    ///
    fn create_wrappers_for_traits(&mut self) {
        let drop_native_ref: TokenStream = quote! {
            extern "C" {
                #[link_name = #DROP_FUNCTION_SYMBOL_NAME]
                fn drop_native_ref(input: *mut std::ffi::c_void);
            }
        };
        self.wrappers_impls.extend(drop_native_ref);

        let limit_lifetime: TokenStream = quote! {
            fn limit_lifetime<'a, T: ?Sized>(r: &'static T, _: &'a ()) -> &'a T {
                r
            }
        };
        self.wrappers_impls.extend(limit_lifetime);

        let limit_lifetime_mut: TokenStream = quote! {
            fn limit_lifetime_mut<'a, T: ?Sized>(r: &'static mut T, _: &'a mut ()) -> &'a mut T {
                r
            }
        };
        self.wrappers_impls.extend(limit_lifetime_mut);

        for (custom_type, functions) in &self.extern_module_translator.user_traits {
            if custom_type.rust_type == RustWrapperType::Trait {
                let wrapper_name = Ident::new(&custom_type.wrapper_name, Span::call_site());
                let generated_functions =
                    generate_trait_methods(functions.iter(), &custom_type.wrapper_name);
                let generated_wrapper_impl: TokenStream = quote! {
                    pub struct #wrapper_name(std::sync::atomic::AtomicPtr<std::ffi::c_void>);
                    impl super::#wrapper_name for #wrapper_name {
                        #(#generated_functions)*
                    }

                    impl #wrapper_name {
                        fn new(inner: *mut std::ffi::c_void) -> Self {
                            Self(std::sync::atomic::AtomicPtr::new(inner))
                        }
                    }

                    impl Drop for #wrapper_name {
                        fn drop(&mut self) {
                            unsafe { drop_native_ref(self.0.load(std::sync::atomic::Ordering::Relaxed)) }
                        }
                    }
                };
                self.wrappers_impls.extend(generated_wrapper_impl);
                let extern_link_functions = functions.iter().map(|function| {
                    let function_name = &function.name;
                    let export_function_name =
                        format!("{EXPORTED_SYMBOLS_PREFIX}${wrapper_name}${function_name}");
                    let function_name = Ident::new(
                        &format!("{EXPORTED_SYMBOLS_PREFIX}{wrapper_name}_{function_name}"),
                        Span::call_site(),
                    );
                    let return_type = match &function.return_type {
                        Some(WrapperType {
                            original_type_name,
                            rust_type: RustWrapperType::Primitive | RustWrapperType::FieldlessEnum,
                            ..
                        }) => original_type_name.clone(),
                        Some(WrapperType {
                            original_type_name, ..
                        }) => parse_quote! { *mut #original_type_name },
                        _ => parse_quote! { () },
                    };
                    let mut args = prepare_extern_function_signature(function);
                    if let Some(self_arg) = args.first_mut() {
                        *self_arg = parse_quote! {_self: *mut std::ffi::c_void}
                    }
                    quote! {
                        extern "C" {
                            #[link_name = #export_function_name]
                            fn #function_name(#args) -> #return_type;
                        }
                    }
                });
                self.wrappers_impls.extend(extern_link_functions);
            }
        }
    }

    fn create_wrappers_for_exception_trait(&mut self) {
        let exception_types_names_iter = self
            .extern_module_translator
            .rust_types_wrappers
            .unordered_iter()
            .filter_map(|wrapper| {
                if matches!(wrapper.rust_type, RustWrapperType::Exceptions(_)) {
                    Some(wrapper.wrapper_name.clone())
                } else {
                    None
                }
            })
            .collect::<Vec<String>>();

        self.extern_module_translator
            .exception_trait_methods
            .iter()
            .flat_map(|function| {
                exception_types_names_iter
                    .clone()
                    .iter()
                    .map(|wrapper_name| {
                        create_extern_function_for_exception_trait_method(wrapper_name, function)
                    })
                    .collect::<Vec<_>>()
            })
            .collect::<Vec<_>>()
            .into_iter()
            .for_each(|f| self.register_extern_function(f));
    }

    fn create_wrappers_for_global_functions(&mut self) {
        self.extern_module_translator
            .global_functions
            .iter()
            .map(create_extern_global_function)
            .collect::<Vec<_>>()
            .into_iter()
            .for_each(|f| self.register_extern_function(f));
    }

    fn create_wrappers_for_strings(&mut self) -> anyhow::Result<()> {
        let wrapper = WrapperType {
            original_type_name: syn::parse_str("String").unwrap(),
            wrapper_name: "RustString".to_owned(),
            rust_type: RustWrapperType::String,
            reference_parameters: Some(ReferenceParameters::shared()),
            impl_traits: vec![],
        };
        let original_type_name = &wrapper.original_type_name;
        let wrapper_name = &wrapper.wrapper_name;

        let (_, new_function) = self
            .extern_module_translator
            .translate_function(&parse_quote! { fn new() -> #original_type_name; })?;
        let new_extern_function =
            create_extern_associated_function_for_custom_type(wrapper.clone(), &new_function);

        let from_c_str_extern_function = create_from_c_str_extern_function(wrapper.clone());

        let (_, as_mut_ptr_function) = self.extern_module_translator.translate_function(
            &parse_quote! { fn as_mut_ptr(self: &#original_type_name) -> &mut u8; },
        )?;
        let as_mut_ptr_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &as_mut_ptr_function);

        let (_, len_function) = self
            .extern_module_translator
            .translate_function(&parse_quote! { fn len(self: &#original_type_name) -> usize; })?;
        let len_extern_function =
            create_extern_function_for_custom_type(wrapper_name, &len_function);

        let clone_extern_function = create_clone_extern_function(wrapper.clone());

        let drop_extern_function = create_drop_extern_function(wrapper.clone());

        [
            new_extern_function,
            from_c_str_extern_function,
            as_mut_ptr_extern_function,
            len_extern_function,
            clone_extern_function,
            drop_extern_function,
        ]
        .into_iter()
        .for_each(|f| self.register_extern_function(f));
        Ok(())
    }

    fn create_wrappers_for_clones(&mut self) {
        self.extern_module_translator
            .rust_types_wrappers
            .unordered_iter()
            .flat_map(|wrapper| match wrapper.rust_type {
                RustWrapperType::Trait
                | RustWrapperType::String
                | RustWrapperType::Primitive
                | RustWrapperType::FieldlessEnum
                | RustWrapperType::ExceptionTrait
                | RustWrapperType::Exceptions(_) => vec![],
                _ => vec![
                    create_clone_extern_function(wrapper.clone()),
                    create_drop_extern_function(wrapper.clone()),
                ],
            })
            .collect::<Vec<_>>()
            .into_iter()
            .for_each(|f| self.register_extern_function(f));
    }
}